The present invention relates to the field of perfumery. It concerns more particularly a cap (1) for a container (2) housing a consumer product, comprising a device (7, 11) capable of diffusing a volatile substance inside said container, said device being formed of a cap liner element (8, 12) carrying the volatile substance and of a barrier element (10, 14) lodged between the cap liner element and the interior of the container, wherein said barrier element is formed of a membrane permeable to the vapors of the volatile substance and impermeable to the consumer product, so as to enable molecular diffusion of the volatile substance""s vapors inside the closed container.
Consumer products such as heavy-duty detergents and bleaches, which typically may contain chlorine-releasing agents, often diffuse unpleasant odors and, moreover, are known to be difficult to perfume. In fact very few perfumes are stable in such media. The present invention relates more particularly to a system for perfuming the headspace of aggressive liquid media, namely bleaches or bleach containing household products, contained in a bottle, such that the user smells a pleasant odor when opening the bottle or pouring the contents thereof, but no direct contact between the perfume and the medium occurs.
The difficulty to perfume aggressive media, in particular hypochlorite bleach-containing products (hereafter referred as xe2x80x9cbleachxe2x80x9d), is a well-known problem in the field of household cleaners. This problem has a double aspect: on the one hand, the perfume may be altered by the aggressive base, and on the other hand, the activity of the product, measured as the available chlorine content, can also be degraded as the result of the presence of perfuming ingredients susceptible of reacting with the hypochlorite ion.
A few attempts to circumvent the aforementioned drawbacks by perfuming the headspace in the container above the product have been published. For instance, U.S. Pat. No. 4,858,758 describes a container equipped with a closure capable of delivering perfume into the headspace above granular products such as solid bleach. In this device, the perfume is contained in an absorbent reservoir placed in the closure, said reservoir being faced with a perforated polymer coating. This facing allows the fragrance materials to macroscopically diffuse through the apertures. Clearly, this design is limited to use only with solid products. Moreover, the manufacture of this device is complicated by the requirement of perforations in the facing.
More recently, a device was proposed in EP 663 883-B1 which overcomes the limitation of product applicability of the aforementioned prior art, whilst relying on a distinct fragrance delivery system. EP 663 883 discloses a device comprising a compressible adsorbent material impregnated with perfume and lodged in the closure or cap of a container. In one embodiment, the material is faced with polyethylene to protect it from the aggressive medium held within the container. The device acts as both the sealing liner for the closure as well as a reservoir for the perfume. When the closure is tightened, the physical nature of the reservoir causes a dose of the fragrance to be excreted therefrom, by mechanical compression, into the headspace above the product. Despite the fact that this device can suit any kind of product stocked in a container (i.e. liquid or dry), the release of the perfume into the headspace relies on a mechanical action. In other words, the system needs external activation to be effective.
The present invention avoids the drawbacks of the above-mentioned prior art inventions by providing a device which makes it possible to efficiently perfume the headspace above both liquid and solid products. The perfume is effectively segregated from the aggressive medium, thus preserving the quality of its fragrance, whilst also preventing decomposition of the product housed in the container. Finally, no external activation is required for working the invention.
We have now discovered that it is possible to perfume the headspace of a liquid composition stocked in a container, without requiring mechanical activation to cause dosing of the fragrance and without being limited to use with only solid products. Moreover, the user can perceive a pleasant scent when opening the container or pouring its contents, even when the latter have an unpleasant odor.
As previously mentioned, the present invention concerns a cap (1) for a container (2) housing a consumer product, comprising a device (7, 11) capable of diffusing a volatile substance inside said container, said device being formed of a cap liner element (8, 12) carrying the volatile substance and of a barrier element (10, 14) lodged between the cap liner element and the interior of the container, wherein said barrier element is formed of a membrane permeable to the vapors of the volatile substance and impermeable to the consumer product, so as to enable molecular diffusion of the volatile substance""s vapors inside the closed container. The volatile substance""s vapors can diffuse through the membrane, thus creating a perfumed headspace above the product, for example a cosmetic or cleaning composition contained in the closed container. The diffusion of the volatile substance through the membrane into the headspace of the container occurs on a molecular level, rather than, as disclosed in the prior art, being mechanically dosed or being released through macroscopic apertures. When the user removes the cap from the container, the perfume diffused above the active composition is released out of the bottle and perceived by the user. Unlike the usual consumer products of this type, wherein the composition itself is perfumed, the perfume, according to the present invention, is isolated from the product base.
As it will become more apparent upon reading the specific examples given hereinafter, the device according to the invention offers several advantages. In addition to the fact that the invention is particularly advantageous to mask bad odors, which can diffuse from compositions that cannot be easily perfumed when the user opens the container and pours its content, said device may be applied to both liquid and solid products, because the membrane present in the diffusing element lodged in the cap or closure of the container is permeable to the volatile substance carried by the cap liner member but does not contain apertures. The perfume or any other volatile substance can diffuse from its carrier to the headspace through the membrane permeable to volatiles, but the latter is impermeable to the liquid product, thus preventing the latter from contact with the perfume housed in the cap. Since the perfume is effectively segregated from the medium inside the container, the stability issues, such as loss of odor quality and reduction of bleach activity, normally associated with aggressive consumer product bases are not encountered. This will become apparent from the stability data presented in a comparative example hereinafter, which shows that the available chlorine level of a bleach product remains substantially constant with time when contained in a bottle provided with a cap or closure according to the invention.
Therefore, whereas currently only a handful of perfume raw materials are stable and can be used in chlorine bleaches, the present invention allows a greatly expanded selection of perfume materials, the latter being no longer limited by the nature of the base. On the other hand, the unpleasant odor of the unperfumed bleach product is still counteracted by means of the headspace volatiles accumulated inside the container and which are released upon opening the latter.
The cap according to the invention, and the container carrying such a cap are therefore particularly useful for consumer products such as liquid products for textile treatment, in particular those that cannot be easily perfumed, as well as all-purpose cleaners, bleaches, etc. However, it is clear that its utilization is not limited to the above-mentioned products, and the packaging equipped with a removable cap according to the invention can suit any other usual detergent application, such as fabric softeners or detergent compositions, or cleaning products for dishes or varied surfaces for domestic as well as industrial use. The system can also be used in other applications and traditionally perfumed products, namely hygiene, hair care, or hair coloring products.
Furthermore, although the invention is particularly adapted for the diffusion of perfumes inside bottles containing consumer products typically fragranced, the caps according to the invention can also be employed to achieve other effects, such as the diffusion of volatile agents like antibacterial, bactericide, insecticide, insect repellent agents or other volatile active substances.
According to one embodiment of the present invention, the element provided in the cap and capable of diffusing a volatile substance such as a perfume material is lodged inside the cap and serves as a cap liner. The cap liner is assembled with a membrane formed of a polymeric film affixed, by heating or another method, to the cap liner""s surface facing the inside of the bottle, the liner being impregnated with a desired amount of perfume oil. The liner can be formed of any current cap liner material which is capable of being impregnated with one or more perfuming ingredients. The affixed film is solid, covers the entire face of the liner, and does not contain apertures. The polymer membrane allows diffusion of volatile materials on a molecular scale through it to the inside of the bottle so as to populate the headspace above the composition in the container with the volatile materials while not allowing the contents of the container to contact the perfume-impregnated liner material.
In another embodiment of the invention, the cap comprises a chamber in which the fragrance is housed. Said fragrance can be, for example, in liquid form. The chamber for the fragrance is provided with a polymeric film, the diffusion membrane, which acts as a semi-permeable barrier for allowing diffusion of the perfume volatiles into the container, whilst preventing any liquid contained in the bottle from affecting the cap liner and the perfume it carries.
According to the invention, the fragrance is diffused out of the cap liner element carrying the latter, through the membrane, into the headspace of the bottle on a molecular scale. The membrane does not require apertures for the diffusion, nor does the fragrance release require mechanical activation. When the bottle is opened, the user clearly perceives the fragrance volatiles accumulated above the liquid or solid contents of the bottle, and this fragrance is perceivable even after the bottle has been opened for several minutes. When the cap is replaced, the headspace above the liquid in the container is replenished with fragrance, since the diffusing element is active without mechanical activation, until all the perfume is exhausted.
These and other aspects of the invention shall become apparent from the drawings and description hereafter.